bug#72559: 31.0.50; profiler-report-write-profile produced unreadable data

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: pipcet@protonmail.com,  yantar92@posteo.net,  72559@debbugs.gnu.org
> Date: Sat, 17 Aug 2024 13:35:07 -0400
> 
> >> I don't think we want to write them as function objects, because then
> >> we'll again bump into the problem that some function objects contain
> >> unprintable objects like buffers.
> > But Emacs 29 does succeed there, at least in my testing, including
> > when the profile shows byte-compiled functions.  So how come Emacs 30
> > cannot?
> 
> Emacs-29 did:
> 
>     (defun profiler-format-entry (entry)
>       "Format ENTRY in human readable string.
>     ENTRY would be a function name of a function itself."
>       (cond ((memq (car-safe entry) '(closure lambda))
>              (format "#<lambda %#x>" (sxhash entry)))
>             ((byte-code-function-p entry)
>              (format "#<compiled %#x>" (sxhash entry)))
>             ((or (subrp entry) (symbolp entry) (stringp entry))
>              (format "%s" entry))
>             (t
>              (format "#<unknown %#x>" (sxhash entry)))))
> 
>     (defun profiler-fixup-entry (entry)
>       (if (symbolp entry)
>           entry
>         (profiler-format-entry entry)))
> 
> IOW it did not save the actual function object but only some kind of
> "name" (like we do now).
> 
> And then when using such a saved backtrace, the `stringp` above made it
> print just that name.  My suggestion above (as in the patch below) just
> re-instates that previous behavior.

Thanks, installed on the emacs-30 branch, and closing the bug.